Understanding Mechanical Ventilators:
Mechanical ventilators, commonly known as breathing machines or respirators, have become one of the most crucial life-saving medical devices during the ongoing COVID-19 pandemic. As the number of coronavirus patients with respiratory failure continues to rise globally, hospitals and healthcare systems have struggled to manage the huge demand for ventilators. This article provides an overview of mechanical ventilators, how they work, their importance during the pandemic and other key aspects.
What are Mechanical Ventilators?
A mechanical ventilator, also called a respirator, is a medical device used to provide respiratory support to patients who are unable to breathe sufficiently on their own or require assistance with breathing. These machines pump oxygenated air into the patient’s lungs via an endotracheal (ET) tube or tracheostomy tube inserted through the mouth or throat. This process of mechanical breathing is called ventilation.
Modern ventilators are equipped with advanced sensors, computers and electronic controls to deliver precise breaths based on the patient’s needs, including adjustments to volume, flow, inspiration time and other parameters. Portable ventilators have also been developed that can operate on batteries for limited mobility. Ventilators range in complexity and features from basic models suitable for emergency response to highly advanced systems used in hospitals.
How Mechanical Ventilators Work
In simple terms, a ventilator performs the job of breathing for patients who cannot breathe on their own or adequately. During inspiration, the ventilator pushes air into the lungs via the ET/tracheostomy tube. The air mix contains varying concentrations of oxygen tailored as per the patient’s condition.
As the lungs fill with gas, the diaphragm and chest wall are stretched, mimicking natural breathing. During expiration, the ventilator passively allows air to flow out of the lungs or may apply positive pressure to help fully empty them. Various modes like continuous mandatory ventilation (CMV), synchronized intermittent mandatory ventilation (SIMV), pressure support ventilation (PSV) etc. are used depending on the situation.
Sophisticated ventilators also have exhaustive monitoring capabilities like measuring pressures, volumes, oxygen levels and more during inspiration and expiration phases. Advanced parameters like PEEP, compliance etc. are adjusted continuously to optimize gas exchange and prevent lung collapse. Ventilation is highly individualized as per each patient’s unique clinical profile and response.
Role of Ventilators in COVID-19 Pandemic
COVID-19 primarily attacks the respiratory system by causing pneumonia and acute respiratory distress syndrome (ARDS) in severe cases. Up to 12% of confirmed coronavirus patients globally require intensive care support and mechanical ventilation due to life-threatening respiratory failure.
In places witnessing a surge like Italy, Spain and New York, the pandemic has pushed healthcare systems beyond full capacity. Demand for critical care beds and ventilators skyrocketed as tens of thousands of patients flooded hospitals. Not having enough ventilators meant difficult decisions around allocating limited resources and prioritizing patients with the best chance of survival.
Countries scrambled to find ways to boost ventilator production and stockpiles or create makeshift alternatives. Engineers devised methods to convert regular breathing devices, Ambu bags and even CPAP machines into makeshift ventilators. Some companies 3D printed ventilator parts or received expedited approvals to bridge shortages. However, the pandemic still exposed gaps in preparedness, ventilator manufacturing infrastructure and supply chain resilience.
Demand Surge and Rationing
The most severe COVID-19 cases develop acute respiratory distress syndrome (ARDS), a life-threatening lung injury and inflammation that requires mechanical ventilation. Without it, mortality can be as high as 80-90%. However, limited ventilator availability meant rationing was sometimes necessitated early on.
Guidelines were issued in some places on how to prioritize scarce resources to maximize benefits, like prioritizing those most likely to survive. However, rationing evoked ethical debates around age discrimination and deciding who lives or dies. Some places asked physicians to decide between patients based on chance of survival or delaying intubation as long as possible.
While countries worked hard to boost production and supply in phases, it was estimated the US alone required a several-fold increase – from 160,000 ventilators before the pandemic to up to 1 million beds. As cases grew exponentially versus linear manufacturing scales, it was a race against time to meet surging needs in the short run using multiple efforts.
Ventilator Design Changes
In response to the pandemic, engineers also focused on developing simpler, easier to mass produce ventilator models that could serve more patients. Some aimed at low-cost open-source designs that could be produced locally using easily available parts.
Concepts were evaluated that allowed multiple patients to share one ventilator unit through splitting devices or ventilator splitting kits. Other innovations included portable emergency ventilators that could operate for days without electricity and be used in field hospitals.
Some changes involved including basic but critical accessories like bacterial filters, heat-moisture exchangers or cough assist mechanisms. Design modifications also accounted for COVID-19 risks like managing aerosolization during tube disconnection or viral contamination of ventilator surfaces. Many improvised changes bridged shortages but also raised questions around long term safety and efficacy.
As the COVID-19 continues to spread globally, mechanical ventilators will remain a crucial tool in the fight against this disease. However, the pandemic has exposed vulnerabilities in preparedness and supply that need addressing. There is a pressing need to ramp up domestic ventilator manufacturing capacity and stockpiles significantly.
Governments must develop resilient supply chains, strategic reserves and local alternatives. Hospitals also need updated ventilator protocols and surge plans for mass critical care. Engineers will play an important role in innovating lower cost portable ventilator solutions suited for pandemics. Overall, ventilator preparedness is a key pandemic response lesson as future outbreaks remain a threat.
Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
